Picking mechanism for looms for weaving

ABSTRACT

A weaving loom in which warp yarns are divided into an upper and a lower shed through which an upper and a lower gripper shuttle are respectively picked simultaneously, each from an opposite side of the loom; and a weft yarn presenter at each side is moved up and down to supply either shuttle with weft alternately.

- United States Patent Porter 5] May 30, 1972 [54] PICKING MECHANISM FOR LOOMS [56] References Cited FOR WEAVING UNITED STATES PATENTS 2 1 [7 1 s England 2,285,793 6/1942 Baker ..139/20 [73] Assignee: Wilson 8: Longbottom Limited, Barnsley, 3,330,305 7/1967 Svaty et a1. ..139/20 England 3,530,902 9/1970 Stingl 139/122 [22] Filed: 1970 Primary Examiner-Henry S. Jaudon [211 App]. No.: 11,797 Attorney-Norris & Bateman 57 ABSTRACT [30] Foreign Application Priority Data l A weaving loom in which warp yarns are divided into an upper Feb. 18, 1969 Great Britain ..8,679/69 and a lower shed through which an upper and a lower gripper shuttle are respectively picked simultaneously, each from an [52] US. Cl ..l39/20, 139/125 opposite side f the loom; and a fl yam presenter at h [51] Int. Cl. ..D03d 17/24 side is moved up and down to supply either shuttle with f [58] Field of Search ..139/20, 21, 22, 122, 125, 126, alternately 12 Claims, 16 Drawing Figures Patented May 30, 1972 3,665,970

8 Sheets-Sheet l Patented May 30, 1972 3,665,970

8 Sheets-Sheet 2 Patented May 3Q, 1972 8 Sheets-Sheet 3 Patented May 30, 1972 8 Sheets-Sheet 4 0 m mmmw b7: m w a o. 2+

Patented May 30, 1972 8 Sheets-Sheet 5 vm x 00 00000 0 Omv\ @Q Patented May 30, 1972 8 Sheets-Sheet 6 Patented May 30, 1972 8 Sheets-Sheet 7 Patented. May 30, 1972 8 Sheets-Sheet 8 PICKING MECHANISM FOR LOOMS FOR WEAVING This invention relates to improvements in weaving looms employing gripper shuttles. I

It has previously been proposed to employ gripper shuttles in looms for weaving face to face carpeting in which an upper and a lower shuttle are picked simultaneously from the same side of the loom. At least two stationary weft yarn packages, one for each shuttle, have to be provided at each side making a minimum requirement of four packages to supply the shuttles and at least four weft yarn presenters, two each side of the loom, to present the yarn to the picked shuttles.

One object of the invention is to reduce the number of weft packages and presenters required for operation of a loom employing an upper and a lower gripper shuttle.

In a loom for weaving in which warp yarns are divided into upper and lower sheds for picking, the invention comprises an upper and a lower gripper shuttle picked simultaneously from opposite sides of the loom through the upper and the lower shed respectively, weft yarn presentation means mounted on the loom at opposite sides of the sheds, the presentation being adapted for supplying weft yarns from weft packages to each shuttle, and means for moving each presentation means upwards into a raised position for supplying the upper shuttle and downwards into a lowered position for supplying the lower shuttle.

The invention will be further described with reference to the accompanying drawings, in which:

FIG. 1 is a fragmentary and diagrammatic view in perspective of a weaving loom formed according to the invention;

FIG. 2 is a diagrammatic view of the two sheds of warp yarns in the loom in FIG. 1;

FIG. 3 is a side view partly in section of a weft yarn presenting means used in the loom;

FIG. 4 is a fragmentary and diagrammatic view of a cam and lever system for operating the presenter in FIG. 3;

FIG. 5 is a fragmentary elevation of an outer side of a weft cutter mechanism provided on one side of the loom;

FIG. 6 is a fragmentary elevation on a larger scale of an inner side of a similar weft cutter mechanism provided on the other side of the loom; 7

FIG. 7 and 8 are fragmentary end and plan views respectiverly, of the weft cutter mechanism in FIG. 6;

FIGS. 9 and 10 are fragmentary side and plan views respectively of a weft yarn tensioner mechanism used on the loom;

FIG. 11 is a perspective view of a cam for controlling the operation of the tensioner mechanism;

FIGS. 12 and 15 show diagrammatically successive stages in a weaving operation carred out on the loom; and

' FIG. 16 is a fragmentary perspective view of a picked lower gripper shuttle engaging weft yarn presented to the shuttle by weft yarn presentation means during operation of the loom in FIG. I.

Referring to the drawings, the loom in FIG. 1 for weaving textile fabric, for example, face to face pile fabrics including carpets, has a sley 2 mounted on the loom. This sley is oscillated by any suitable known means (not shown) for beating up and is formed with a sley sole 4, a reed 6 and a reed cap or hand top 8. Warp yarns for a suitable supply pass through the reed to a fell 10 of a fabric 12 being woven. These warps are divided in known manner by suitably operated heddles (not shown) into upper, middle and lower sheets 14, 16 and 18 respectively, during shedding, to form an upper shed 20 and a lower shed 22. An upper gripper shuttle 24 and a lower gripper shuttle 26 are cross picked, meaning that the shuttles are simultaneously picked each from an opposite side of the loom, through the upper and lower sheds respectively. The upper shuttle is picked by suitable known picking means (not shown) from upper shuttle boxes 28a and 28b alternatively, the lower shuttle being likewise picked from lower boxes 30a and 3012, both sets of shuttle boxes being mounted on the loom.

The gripper shuttles can be any suitable kind. Appropriately, the shuttles can be of the type described in our co-pending US. application Ser. No. 11,796, filed on Feb. 16, 1970, in which the shuttle has an elongated body formed with a recess in the top thereof containing a gripper device openable to release gripped weft yarn when a movable cam lever 32 (FIG. 2) projecting from a side of the body is pushed inwardly thereof upon the cam lever engaging against a side of a shuttle box. This gripper device comprises two pairs of jaws one pair facing the other and each pair consisting of an upper jaw diverging at one end thereof from a co-acting lower jaw to provide a yarn receiving gap therebetween, and the lower jaw being downwardly movable in response to inward movement of the cam lever, and returnable upwardly against the upper jaw by spring means. In FIG. 16 the shuttle 26 of the above type is shown in which the recess is indicated at 31, one pair of gripper jaws at 33 and the other pair at 35.

Weft yarn 34 and 36 from a package 34a or 360 is supplied at each side of the loom to each shuttle by tubular presenter eyes 38 and 40 respectively, each depending from a presenter arm 42 (FIG. 3) screwed into a slide 44 sliding in generally upright tube 46 formed with elongated slots 48 and 50 accommodating arm 42. Weft yarn passed through presenter eye 38 and 40 from top to bottom thereof is raised to supply yarn to the picked upper shuttle by upward movement of the slide 44 and lowered by downward movement of the slide to supply yarn to the lower shuttle. Each tube 46 is mounted on an opposite end of the sley sole 4 by a bracket 52. A casing 54 of a Bowden cable containing a slide wire 58 abuts at one end against a closure 56 screwed into a lower end of tube 46. The wire 58 freely passes through a passage in the closure 56 and through a passage in a screw 60 to a cable nipple 62 engaged against an end of the screw 60 threaded into a bore in the under-side of the slide 44. An helical compression spring 64 surrounding wire 58 presses at one end against a head of screw 60 and at the other end against the closure 56. Another end 54a of casing 54 (FIG. 4) is located in abutment against a bracket 66 mounted on a lower member 68 of the loom frame rearwardly of the sley. The end of wire 58 from the end 54a passes down a passage in a screw 70 to a cable nipple 72 abutting against screw head 74. Screw 70 with a locking nut 76 thereon is threadably mounted in a pin 78 pivotably supported in a bifurcated bracket 80 provided on a lower end of a lever arm 82 pivotably mounted at 84 on a bifurcated bracket 86 carried by an upper member 88 of the loom frame. Lever arm 82 carries a rotatable cam follower 90 engaging, by action of tension spring 92, against the periphery of a presenter cam 94 affixedly mounted on a rotatably driven middle on half speed shaft 96 which is mounted on the loom and is well known in loom art. As cam 94 is rotated peripheral portion 940 pushes the lever arm 82 to the left of FIG. 4 to pull on the wire 58 which in turn pulls the presenter eye 40 down against the action of the spring 62 into the lowered position in FIG. 3 As the cam rotates further bringing peripheral portion 94b into engagement with the follower 90, the arm swings back to the right under action of the spring 92 to relax the wire 58 so allowing spring 62 to expand and lift the eye 40 into the raised position. The extent to which the eye is raised is governed by the position of an adjustable stop 98 screw mounted in the upper end of tube 46. A similar cable, lever, and presenter cam arrangement is provided to raise and lower the eye 38 but with the cam disposed 180 out of phase with the cam 94. Consequently, as one presenter eye is raised the other is simultaneously lowered.

A weft cutter 100 and 102 are located each adjacent to an opposite selvedge of the fabric 12. These cutters are mounted on a rail 104 which is mounted on the loom and extends lengthwise thereof at the front of the loom over a breast plate 106, also mounted on the loom. When face to face pile fabric is being woven, rail 104 can be the known pile depth gauging rail. Each cutter has an upright front plate 108 with an elongated slot 110 to receive one or more bolts (not shown) securing the cutter to the rail 104. Front plate 108 supports a base plate 112 and two spaced substantially parallel and upright side plates 114 and 116, each formed with a guide slot 118 locating a sliding pin 120 carrying a freely rotatable wheel 122 with a peripheral groove 124. One end of pin 120 freely passes through a weft knife arm 126 formed with a nose 128 and carrying a weft knife blade 130 with a knife edge 132. This knife is outside the sheds and the knife edge faces sideways of the loom away from the warp yarns. A second pin 134 passing through the lower portions of plates 114, 116 is located towards front ends thereof and freely passes through an L shaped selvedge trimmer arm 136 located alongside the plate 116 with an upper end 138 of the trimmer arm extending passed the slot 1 18. A lower branch of arm 136 mounts a substantially vertical selvedge trimmer knife 140 depending through a slot 142 in the base plate 112 and having a knife edge 144 facing the rear of the loom. A depending striker plate 146 mounted on the hand top 8 is arranged to hit the wheel 122 and push it (as shown in FIG. towards the rear plate 108 when the sley moves forward towards the fell (FIGS. 1 and 2) during beating up. This movement of the wheel propels the pin 120 forwards in the direction of arrow A (FIGS. 5 and 6) along the slots 118 and carries the arm 126 in the same direction causing the nose 128 to ride up upon a stationary cam block 148 mounted on the side plate 114 thus pivotally raising the weft knife 130 in the direction of arrow B above weft yarn being propelled to the fell by the sley in a weaving operation (herebelow described with reference to FIGS. 12 to As the pin 120 moves forwards a roller 150 thereon strikes the end 138 of arm 136 which pivots to swing the selvedge knife 140 upwards in the direction of arrow C into the position shown in FIG. 5. With convenience the selvedge knife may be said to be located in the selvedge. Accordingly, the upward swing of the selvedge knife cuts through weft yarns woven into the selvedge to trim a strip 152 (FIG. 1) therefrom to leave a neat edge at the selvedge remaining on the fabric 12. To ensure that this remaining selvedge is firm it is preferred to form the selvedges by a leno weave effected by giving the selvedge warp yarns a leno motion during shedding. A peg 154 depending from the base plate 112 can be provided adjacent to the blade 140 to divert the strip 152 from the body of the fabric. A further peg 156 depending from plate 112 can be provided to divert the warp yarns away from the weft knife 130.

When the sley returns rearwardly, the striker 146 disengages from the wheel 122. The pin 120 is then returned along the slots 118 by action of a return spring 158 encircling pin 134 and having arms 158a and l58b braced against the groove 124 and base plate 112 respectiverly. Returning pin 120 lowers the weft blade 130 into a substantially vertical position a short distance beyond the fell where the blade is held against inadvertent upward displacement by a spring 160. The selvedge blade 140 is lowered by a return spring 162 encircling the pin 134 and having one arm 162a braced against the base plate and another arm l62b hooked into the selvedge trimmer arm 136.

A curved guard plate 101 is disposed over each cutter 100, 102. The plate 101 can be formed, for example, of a clear plastics material and is pivotally mounted on a rod 103 disposed over the rail 104. Edges of the guide plate are located in grooves in blocks 105 mounted on the hand top 8, these blocks sliding along the guard edges as the sley oscillates.

Yarn from the package 34a or 36a passes through a tensioner 164 or 166 before reaching the presenter eye 38 or 40. Each tensioner is of analagous construction illustrated in FIGS. 9 and 10 formed with a girder base of an inverted I..- shape section stationarily mounted on the loom by bolts 170 or the like passing through a top 172 of the girder. A raisable and lowerable tensioner arm 174 is mounted at one end on a shaft 176 rotatably passing through a stationary sleeve bearing 178 mounted on the top 172. A lever arm 180 mounted on the shaft 178 is connected to a U-shaped bracket 184 engaging a cable nipple 182 on a wire 186 of a Bowden cable which has an outer casing engaged by a bracket 188 mounted on a side 190 of the girder. The other end of the Bowden cable is connected to a cam and lever arrangement similar to that shown in FIG. 4 except that the cam 94 therein is replaced by a tensioner cam 192 (FIG. 11) afiixedly mounted on the half speed shaft 96. Conveniently this can be a double cam each of a generally tear drop shape with lobes or noses 192a thereof disposed at substantially to one another. The tensioner arm 174 is raised when either nose 192a contacts the cam follower and lowered when peripheral portions 192b of the tensioner cam contact the follower. The arm 174 is therefore raised and lowered twice per revolution of the half speed shaft.

A triangular shaped weft guide or eye 194 formed for example, of wire is mounted on the arm 174, an apex of the triangle depending downwards. When the tensioner arm is lowered the eye 194 is located between a pair of stationary hollow, open ended, frustoconically shaped yarn guides 196 mounted on the girder side with the narrow ends or cones apices facing one another. A pair of weft yarn guiding cymbals 198 formed, for example, of porcelain are disposed between the stationary weft supply package and the eye 194. Both cymbals are freely mounted at their centers on a spindle 200 mounted on the side 190. One cymbal is pressed by a relatively strong coil spring 202 against the other which abuts against a fixed stop 204 on the spindle. The spring pressure is such that the weft yarn is firmly clamped between the cymbals 198 to prevent yarn being drawn from the package when the eye 194 is raised by the arm 174. On the arm 174 being lowered, a charnferred end 206 of a hooked shaped peg 208 mounted on the arm 174 is pushed between the cymbals 198 prying them apart to release the yarn. The yarn is also guided by known guide eyes 210 and between another pair of cymbals 212 one lightly pushed towards the other by a weak spring 214.

The guides 194 and 196 are shaped with diverging sides to deflect the weft yarn to prevent it becoming tangled around these guides and the arm 174 should sudden raising and lowering of the guide 194 cause the yarn to whip.

Another tensioner cam, lever and Bowden cable arrangement actuates the arm 174 in the tensioner 164, and in this case the cam is in phase with the cam of tensioner 166 so that both the arms 174 are raised and lowered simultaneously.

The raising and lowering of the presenter eyes 38 and 40 and the tensioner arms 174 are coordinated with the picking of the shuttles 24 and 26 and the beating up motion of the sley 2 to give a weaving sequence shown in FIGS. 12 to 15 in which only the lower sheet 18 of the warp yarns is shown for clarity, and the weft knife of cutter 102 is indicated at 130 to distinguish it from the weft knife 130 of the cutter 100.

In FIG. 12, the sley 2 is in the back position the upper shuttle 24 and the lower shuttle 26 are in the upper and lower shuttle boxes 28a and 3012 respectively, and eyes 38 and 40 are in the raised and lowered position respectively. Both tensioner arms 174 are lowered with the pegs 208 thereon holding cymbols 198 apart.

The gripper shuttles are picked simultaneously from opposite sides ofthe loom and in passing the presenter eyes the upper shuttle 24 grips the weft yarn 34 and the lower shuttle grips the yarn 36. This is shown with respect to the lower shuttle 26 being picked in the direction X in FIG. 16 where the weft yarn 36 positioned by the presenter eye 40 is in the process of being engaged by the jaws 33. Yarn 34 is carried into the upper shed and yarn 36 into the lower shed. A section of yarn 34 extending from shuttle 24 to the selvedge of the fabric 12 is thus pulled against the edge of the weft knife 130' and severed, while yarn 36 is likewise severed by the knife 130. The situation now reached is shown in FIG. 13.

At opposite sides of the loom, shuttles 24 and 26 enter the upper and lower boxes 28b and 30a as shown in FIG. 14 and release the picks of weft yarn which are carried toward the fell 10 by the sley 2 moving forwards to beat up. As the sley moves, the tensioner arms 174 are simultaneously raised pulling sections of the weft yarns, between the cone guides 196, upwards transversely to the general direction of travel of the yarn. This upward movement of the am 174 releases the cymbals 198 which grip the weft yarns so that the pull of tensioner arms results in the last inserted picks being pulled longitudinally some distance back through the sheds to straighten the picks during beating up and reduce the length of the loose tails of weft projecting from the selvedges. This straightening of the picks results in a firmer woven fabric of neat appearance. When the sley approaches the fell the knives 130, 130, indicated in dotted lines, are raised to avoid the picks which pass beneath. The selvedge knives 140 described with reference to FIGS. 5 to 8 are also raised to trim the selvedges by cutting through picks of weft previously woven into the selvedges.

Shedding now takes place and the sley moves rearwardly. This allows the weft knives 130, 130 to drop as shown in FIG. 15, and hook behind the portions of the weft yarns 34, 36 extending from the selvedges to the presenter eyes 38 and 40 which now move into the lowered and raised positions respectively. Then the arms 174 are lowered and pry the cymbals 198 apart. The situation is now essentially the same as that shown in FIG. 12 except that the shuttle 26 when next picked will pull the yarn 34 through the lower shed and the yarn 36 will be inserted into the upper shed by the shuttle 24.

A great advantage .of the loom described above with reference to the drawings is that at each side of the loom the same presenter can be used to supply both shuttles with yarn from the same package.

If desired weft yarns of differing materials, colors, grades etc., can be provided at one or both sides of the loom, each yarn having its own presenter which can supply both the shuttles but also has a movement enabling presentation of a particular yarn to a shuttle to be avoided when desired so that the differing yarns can be supplied to either shuttle in a variable sequence.

What l claim is:

1. A loom for weaving in which warp yarns are divided into upper and lower sheds, comprising upper and lower gripper shuttles picked simultaneously from opposite sides of the loom through the upper and lower sheds, respectively, weft yarn presentation means mounted on the loom at opposite sides of the sheds, each presentation means being adapted for supplying weft yarns from weft packages to each shuttle, and means for moving each presentation means upwards into a raised position for supplying the upper shuttle and downwards into a lowered position for supplying the lower shuttle.

2. A loom as defined in claim 1, including beating up means mounted on the loom for forwardly propelling picks of weft inserted into the sheds by the picked shuttles towards a fell of a fabric woven on the loom, weft yarn cutting means mounted on the loom at a side of the sheds, said weft yarn cutting means being movable from a weft yarn cutting position to a noncutting position during beat up and back to said yarn cutting position after beat up, whereby a portion of weft yarn extending from a forwardly propelled pick to each said presentation means is avoided by movement of the cutting means into the non-cutting position during beat up and said portion is drawn against the cutting means in the cutting position after beat up by one of said picked shuttles for severing said portion from the beaten up pick.

3. A loom as defined in claim 2 wherein the cutting means comprises a knife pivotally mounted on the loom, means for pivoting the knife upwards during beat up, and means for lowering the knife after beat up.

4. A loom as defined in claim 3, wherein the knife is mounted on an arm, said arm being mounted on a pivot for upward and downward movement about said pivot, a stationary member mounted on the loom, said member being formed with a slot extending generally along a direction from a front to a rear of the loom, the pivot being located in said slot, a striker member mounted on the beating up means, said striker member being adapted for pushing the pivot forwardly along said slot during beat up, cam means mounted on the member, and the amt adapted for riding up upon said cam means during forward movement of the pivot whereby the arm and knife are raised, and spring means for propelling the pivot rearwardly back along the slot whereby the knife is lowered.

5. A loom as defined in claim 1 including a cutting blade mounted in the loom, said blade being movable for trimming a strip from off a selvedge of a fabric woven on the loom, and means for moving the blade.

6. A loom as defined in claim 1 including beating up means mounted on the loom for beating up picks of weft yarn inserted into the sheds by the picked shuttles, and weft yarn pulling means mounted on opposite sides of the loom for moving said picks longitudinally during beat up.

7. A loom as defined in claim 6 wherein each pulling means comprises first, second, and third weft yarn guiding means mounted on the loom, the guiding means being disposed for the passage of a said weft yarn through the first, second, and third guiding means in succession from a said package to a said presentation means, the second guiding means being movable in one direction relatively to said first and third guiding means for pulling on the weft yarn extending between said first and third guiding means, means for moving said second guiding means in said one direction during beat up and for returning said second guiding means in the opposite direction after beat up, weft yarn clamping means mounted on the loom, said clamping means being disposed for the passage of weft yarn therethrough extending from the said package to the first guiding means, means operating said clamping means for clamping the weft yarn during beat up, and means for opening said clamping means after beat up.

8; A loom as defined in claim 7, wherein the first and third guiding means are stationary, the second guiding means being mounted on an arm, said arm being mounted on a pivot for upward and downward movement about the pivot, the pivot being mounted on the loom, means for pivotally raising the arm during beat up and for lowering the arm after beat up, a pair of weft yarn clamping members for the passage of weft yarn therebetween extending from the said package to the said first guiding means, at least one said clamping member being movable relatively to other, spring means applying weft yarn clamping pressure to a said movable clamping member for pushing the clamping member into weft clamping relation with the other clamping member, a projection mounted on the arm, said projection being adapted for insertion between said clamping members when the arm is lowered whereby the clamping members are moved apart, and the projection being adapted for removal from between the clamping members when the arm is raised.

9. A loom as defined in claim 7, including cable means having a movable slide wire for moving said second guiding means, and drive means connected to said slide wire for moving said wire and thereby moving said second guiding means in predetermined fashion.

10. A loom as defined in claim 9, said slide wire drive means comprising an arm for moving the wire, said arm mounted on a pivot for pivoting movement about the pivot, said pivot mounted on the loom, a drive shaft rotatably mounted on the loom, a cam afiixedly mounted on the shaft, and said arm cooperating with said cam whereby the arm is pivotably moved.

11. A loom as defined in claim 1, including beating up means mounted on the loom for propelling picks of weft inserted into the sheds by the picked shuttles towards a fell of a fabric woven on the loom, each presentation means comprising a weft yarn presenter eye for presenting weft to one of said shuttles, a slide member on which said presentation eye is mounted, a guide member mounted on said heating up means, said slide member mounted on said guide member for upward and downward movement, cable means having a movable slide wire connected to said slide member, and drive means connected to said slide wire for moving said wire and thereby moving said slide member in a predetermined fashion.

12. A loom as defined in claim 11, said drive means including an arm for moving the slide wire, said arm mounted on a pivot for pivoting movement about the pivot, said pivot mounted on the loom, a driven shaft rotatably mounted on the loom, a cam afiixedly mounted on the shaft, and said arm cooperating with said cam whereby the arm is moved. 

1. A loom for weaving in which warp yarns are divided into upper and lower sheds, comprising upper and lower gripper shuttles picked simultaneously from opposite sides of the loom through the upper and lower sheds, respectively, weft yarn presentation means mounted on the loom at opposite sides of the sheds, each presentation means being adapted for supplying weft yarns from weft packages to each shuttle, and means for moving each presentation means upwards into a raised position for supplying the upper shuttle and downwards into a lowered position for supplying the lower shuttle.
 2. A loom as defined in claim 1, including beating up means mounted on the loom for forwardly propelling picks of weft inserted into the sheds by the picked shuttles towards a fell of a fabric woven on the loom, weft yarn cutting means mounted on the loom at a side of the sheds, said weft yarn cutting means being movable from a weft yarn cutting position to a non-cutting position during beat up and back to said yarn cutting position after beat up, whereby a portion of weft yarn extending from a forwardly propelled pick to each said presentation means is avoided by movement of the cutting means into the non-cutting position during beat up and said portion is drawn against the cutting means in the cutting position after beat up by one of said picked shuttles for severing said portion from the beaten up pick.
 3. A loom as defined in claim 2 wherein the cutting means comprises a knife pivotally mounted on the loom, means for pivoting the knife upwards during beat up, and means for lowering the knife after beat up.
 4. A loom as defined in claim 3, wherein the knife is mounted on an arm, said arm being mounted on a pivot for upward and downward movement about said pivot, a stationary member mounted on the loom, said member being formed with a slot extending generally along a direction from a front to a rear of the loom, the pivot being located in said slot, a striker member mounted on the beating up means, said striker member being adapted for pushing the pivot forwardly along said slot during beat up, cam means mounted on the member, and the arm adapted for riding up upon said cam means during forward movement of the pivot whereby the arm and knife are raised, and spring means for propelling the pivot rearwardly back along the slot whereby the knife is lowered.
 5. A loom as defined in claim 1 including a cutting blade mounted in the loom, said blade being movable for trimming a strip from off a selvedge of a fabric woven on the loom, and means for moving the blade.
 6. A loom as defined in claim 1 including beating up means mounted on the loom for beating up picks of weft yarn inserted into the sheds by the picked shuttles, and weft yarn pulling means mounted on opposite sides of the loom for moving said picks longitudinally during beat up.
 7. A loom as defined in claim 6 wherein each pulling means comprises first, second, and third weft yarn guiding means mounted on the loom, the guiding means being disposed for the passage of a said weft yarn through the first, second, and third guiding means in succession from a said package to a said presentation means, the second guiding means being movable in one direction relatively to said first and third guiding means for pulling on the weft yarn extending between said first and third guiding means, means for moving said second guiding means in said one direction during beat up and for returning said second guiding means in the opposite direction after beat up, weft yarn clamping means mounted on the loom, said clamping means being disposed for the passage of weft yarn therethrough extending from the said package to the first guiding means, means operating said clamping means for clamping the weft yarn during beat up, and means for opening said clamping means after beat up.
 8. A loom as defined in claim 7, wherein the first and third guiding means are stationary, the second guiding means being mounted on an arm, said arm being mounted on a pivot for upward and downward movement about the pivot, the pivot being mounted on the loom, means for pivotally raising the arm during beat up and for lowering the arm after beat up, a pair Of weft yarn clamping members for the passage of weft yarn therebetween extending from the said package to the said first guiding means, at least one said clamping member being movable relatively to other, spring means applying weft yarn clamping pressure to a said movable clamping member for pushing the clamping member into weft clamping relation with the other clamping member, a projection mounted on the arm, said projection being adapted for insertion between said clamping members when the arm is lowered whereby the clamping members are moved apart, and the projection being adapted for removal from between the clamping members when the arm is raised.
 9. A loom as defined in claim 7, including cable means having a movable slide wire for moving said second guiding means, and drive means connected to said slide wire for moving said wire and thereby moving said second guiding means in predetermined fashion.
 10. A loom as defined in claim 9, said slide wire drive means comprising an arm for moving the wire, said arm mounted on a pivot for pivoting movement about the pivot, said pivot mounted on the loom, a drive shaft rotatably mounted on the loom, a cam affixedly mounted on the shaft, and said arm cooperating with said cam whereby the arm is pivotably moved.
 11. A loom as defined in claim 1, including beating up means mounted on the loom for propelling picks of weft inserted into the sheds by the picked shuttles towards a fell of a fabric woven on the loom, each presentation means comprising a weft yarn presenter eye for presenting weft to one of said shuttles, a slide member on which said presentation eye is mounted, a guide member mounted on said beating up means, said slide member mounted on said guide member for upward and downward movement, cable means having a movable slide wire connected to said slide member, and drive means connected to said slide wire for moving said wire and thereby moving said slide member in a predetermined fashion.
 12. A loom as defined in claim 11, said drive means including an arm for moving the slide wire, said arm mounted on a pivot for pivoting movement about the pivot, said pivot mounted on the loom, a driven shaft rotatably mounted on the loom, a cam affixedly mounted on the shaft, and said arm cooperating with said cam whereby the arm is moved. 